Source code for jldesmear.jl_api.extrap_constant
#!/usr/bin/env python
'''
Extrapolate as: I(q) = B
'''
import extrapolation
import toolbox
import pprint
import os #@UnusedImport
import numpy #@UnusedImport
[docs]class Extrapolation(extrapolation.Extrapolation):
'''I(q) = B'''
name = 'constant'
def __init__(self):
'''set up things'''
self.coefficients = {'B': 0}
def __str__(self):
''':return: a text string showing the functional form'''
form = "constant: I(q) = " + str(self.coefficients['B'])
return form
[docs] def calc(self, q):
'''
.. math::
I(q) = B
:param float q: magnitude of scattering vector
:return: value of extrapolation function at *q*
:rtype: float
'''
if isinstance(q, numpy.ndarray):
basis = numpy.ones_like(q)
else:
basis = 1.0
return self.coefficients['B'] * basis
[docs] def fit_result(self, reg):
'''
Determine the results of the fit and store them
as the set of coefficients in the self.coefficients
dictionary. Called from :meth:`fit()`.
:note: *must* override in subclass otherwise :meth:`fit_result()` will throw an exception
:param reg: statistics registers (created in :meth:`fit()`)
:type reg: StatsRegClass object
'''
self.coefficients['B'] = reg.Mean()[1]
if __name__ == "__main__":
'''show the various routines'''
print("Testing $Id$")
func = Extrapolation
print("using default coefficients")
fit = func()
print(fit.show().strip())
print("I(%g) = %g" % (0.001, fit.calc(0.001)))
print("I(%g) = %g" % (0.02, fit.calc(0.02)))
pprint.pprint(fit.GetCoefficients())
print("#--------------------------")
print("setting coefficients")
fit.SetCoefficients({'B': 0.1})
print(fit.show().strip())
print("I(%g) = %g" % (0.001, fit.calc(0.001)))
print("I(%g) = %g" % (0.02, fit.calc(0.02)))
pprint.pprint(fit.GetCoefficients())
print("#--------------------------")
print("fitting coefficients")
fn = toolbox.GetTest1DataFilename('.smr')
x, y, dy = toolbox.GetDat( fn )
fit = func()
fit.fit(x, y, dy)
print(fit.show().strip())
print("I(%g) = %g" % (x[0], fit.calc(x[0])))
print("I(%g) = %g" % (x[-1], fit.calc(x[-1])))
pprint.pprint(fit.GetCoefficients())